JPH1199370A - Treating agent for heavy metal-containing waste and stabilizing method of heavy metal-containing waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely stabilize a heavy metal-containing waste by incorporating a latent hydraulic material and a boron compound to prepare a treating agent for the heavy metal-containing waste. SOLUTION: The latent hydraulic material used as an essential component does not cause hydration reaction with water alone and, for example, causes hydration reaction with the addition of a stimulating agent and for example, a blast furnace granulated slag or a converter slag is used. In the case of using the blast furnce granulated slag as the latent hydraulic material, one having a particle size corresponding to >=4,000 cm<2> /g Blaine specific surface area is used. The boron compound to be used is preferably a borate compound, particularly sodium tetraborate is preferable in the view point of heavy metal stabilizing effect and profitability. The boron compound is converted to a hardly water soluble heavy metal boride or heavy metal borate by allowing boron ion or boric acid ion generated in the presence of water to react with the metal ion in the heavy metal-containing waste to stabilize the heavy metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste treatment agent effective for insolubilizing and stabilizing heavy metals contained in general waste and industrial waste, and a method for treating the same. In more detail, incinerators and fly ash generated from incinerators and melting furnaces for municipal garbage, industrial waste, sludge, etc., insolubilize heavy metals contained in wastes, and effectively dispose them for stabilization. The present invention relates to a processing agent for a product and a processing method thereof.

[0002]

2. Description of the Related Art In recent years, as wastes generated from cities and factories have increased, wastes containing heavy metals have been required to be sufficiently detoxified for environmental measures. In particular, incineration ash, fly ash and industrial waste of city waste containing heavy metals,
Strict regulations are set for the treatment and disposal of specially managed waste.

Conventionally, when disposing of waste containing heavy metals, a method of mixing with cement, adding water as necessary, and kneading the mixture to prevent elution of heavy metals and the like has been adopted. However, the standard value for elution of heavy metals from landfill waste, which has been applied since 1995, is for lead which is considered to be the most difficult to stabilize.
In the dissolution test based on No. 3, it is required to stabilize to 0.3 mg / l or less, but it is difficult to clear this standard only with cement.

In the case of mixing and hardening waste, which is a typical cement such as ordinary Portland cement, the calcium hydroxide generated in the hydration process promotes hardening of the cement, but excessively hardens the cement. Generated calcium hydroxide increases the pH of the mixture of waste and cement, and increases the solubility of heavy metal ions such as lead, which is an amphoteric element. It is thought that it is damaged.

[0005] In addition, when cement is used, it is good to use it continuously, but when the treatment is interrupted, the remaining processed material will not be removed without cleaning the equipment such as a mixer or kneader. There is a problem such as maintenance workability that solidifies on the container wall.

Further, attempts have been made to stabilize by trapping and stabilizing heavy metal ions by chemical treatment with a sulfur-containing chelating agent or the like. According to this, it is possible to stabilize to below the elution reference value. However, such a drug is not only expensive, but also has insufficient retention of heavy metal ions after the stabilization treatment. There is a problem that the elution amount of heavy metal ions increases.

[0007]

As described above, it is not only difficult to stabilize heavy metal ions below the elution standard with conventional heavy metal-containing waste treating agents and methods, but also to stabilize them. However, at present, there is a problem in the durability and durability of the retention, and there is a concern that secondary pollution may occur over time.

[0008] It is an object of the present invention to stabilize heavy metal-containing waste, and to stabilize the elution of heavy metal ions below a reference value, and to maintain the effect of stabilizing heavy metal ions to completely prevent secondary pollution. It is an object of the present invention to provide a treating agent and a treating method capable of preventing the occurrence of

[0009]

Means for Solving the Problems In view of such circumstances, the present inventors have intensively studied for a treating agent and a treating method that can completely stabilize heavy metal-containing waste, and as a result, have completed the present invention. . That is, the present invention

(1) A treating agent for heavy metal-containing waste, which comprises a latent hydraulic substance and a boron compound;
(2) the treating agent according to the above (1), wherein the latent hydraulic substance is granulated blast furnace slag, (3) the treating agent according to the above (1) or (2), wherein the boron compound is a boric acid compound,
(4) The above (1) to (3) further containing a dispersant and water.
And (5) heavy metal-containing waste, the treatment agent according to any one of the above (1) to (4), and, if necessary, water, and mixing. A method for treating heavy metal-containing waste characterized by kneading, (6) heavy metal-containing waste, the treatment agent according to any one of the above (1) to (4), and adding water as required. (7) Heavy metal-containing waste is incinerated ash, fly ash, contaminated soil, or Prime Minister's Ordinance at a garbage incineration plant. (5) The method for treating heavy metal-containing waste as described in (5) or (6) above, which is an industrial waste containing metals and the like that must satisfy the criteria set forth in No. 5, (8) Notification of the Environment Agency No. 13 The above-mentioned (1) is applied to heavy metal-containing waste in which the pH of the eluate after the dissolution test based on The addition process the treating agent and an acidic substance according to any one of (4) (5) - (7)
(9) Notification of the Environment Agency No. 1
The treatment agent and the basic substance described in any one of the above (1) to (4) are added to a heavy metal-containing waste having a neutral or acidic pH after the dissolution test based on No. 3 for treatment. The processing method according to any one of the above (5) to (8),
(10) A processed product obtained by the processing method according to any one of (5) to (9).

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The latent hydraulic substance used as an essential component in the present invention is a substance that does not undergo hydration reaction with water alone, for example, a substance that undergoes hydration reaction by adding a stimulant or the like. Specific examples of the latent hydraulic substance that can be used include granulated blast furnace slag and converter slag. Among these latent hydraulic substances, granulated blast furnace slag is preferred. These latent hydraulic substances can be used alone or in combination of one or more.

When granulated blast furnace slag is used as a latent hydraulic material, its particle size is 2,000 c.
m ² / g or more can be used.
Those having a size of at least 00 cm ² / g can be used. The greater the Blaine specific surface area, the greater the effect of stabilizing heavy metals, but the higher the production cost and the more economically disadvantageous.

Although the mechanism of the stabilizing effect of the latent hydraulic substance on the heavy metal ions is not necessarily clear, it is considered that the latent hydraulic substance itself has the ability to adsorb heavy metal ions. In addition, the curing reaction of the latent hydraulic substance proceeds by the alkali ions contained in the heavy metal-containing waste, and the resulting various hydration products further strengthen the heavy metal ion exchange ability, diffusion suppression ability and adsorption ability. It is also considered to be expressed in a continuous manner.

The heavy metal stabilizing agent of the present invention (hereinafter referred to as the agent of the present invention) further contains a boron compound as an essential component. Boron compounds react with metal ions in heavy metal-containing wastes by reacting with boron ions and borate ions generated in the presence of water, resulting in heavy metal borides and boric acid heavy metals that are hardly soluble in water. Guessed. By using a boron compound and a latent hydraulic substance together, an effect of stabilizing heavy metals, which has not been obtained conventionally, can be obtained. That is, the heavy metal compound and the heavy metal ion are firmly sealed in the hydrate of the latent hydraulic substance, so that the elution of the heavy metal can be suppressed for a long time, and the heavy metal does not elute even when exposed to acid rain.

The boron compound used in the present invention is not particularly limited, but specific examples thereof include B ₂ H ₆ , B ₄ H ₁₀ and B ₅ H
₉ , borohydrides such as B ₅ H ₁₁ , B ₆ H ₁₀ , B ₁₀ H ₁₄ and derivatives thereof, boric acid compounds, and BO,
Oxygen compounds such as B ₄ O ₅ , B ₂ O ₃ and boryl compounds and derivatives thereof, and BF ₃ , BCl ₃ , BBr ₃ ,
Borohalides such as BI ₃ , B ₂ Cl ₄ , B ₂ Br ₄ , B ₂ I ₄ , tetrafluoroborates and derivatives thereof, borosulfides such as B ₂ S ₃ , borides such as B ₄ C Carbide, boron nitride, borazane, borazene, borazine,
Boron nitride compounds such as borazole, borinoaminoborin, boron amide, and boron imide, and derivatives thereof can be mentioned. In the above, the boric acid compounds include hypoboric acid and salts thereof, tetraborate and potassium tetraborate, calcium tetraborate, silver tetraborate, strontium tetraborate, sodium tetraborate, borax, Tetraborates such as lithium borate, peroxoborates such as peroxoboric acid and sodium peroxoborate,
Various borate esters and the like can be mentioned. Of these boron compounds, boric acid compounds are preferred, and sodium tetraborate is particularly preferred from the viewpoint of heavy metal stabilizing effect and economy. Two or more of these boron compounds may be used in combination.

The amount of the boron compound to be used must be appropriately determined according to the type and particle size of the latent hydraulic substance and the type of waste, particularly the amount of heavy metal eluted. ５００500 parts by weight, preferably 5-150 parts by weight.

The treating agent of the present invention is usually in the form of a powder, but can be handled as a slurry liquid composition. That is, by adding an aqueous solution containing a dispersant and water to the latent hydraulic substance and the boron compound, adding a water-soluble polymer as a thickener as necessary, mixing and kneading, the slurry-like treatment of the present invention Agent can be obtained.

The dispersant used in preparing this liquid composition plays a role in uniformly dispersing the particles. The dispersant may be any one that can uniformly disperse the latent hydraulic substance or the boron compound in water, but it is preferable to avoid those that react with the boron compound to form a complex compound,
For example, cements such as formalin condensate of naphthalene sulfonic acid, formalin condensate of melamine sulfonic acid, and lignin sulfonic acid condensate, and those generally known as dispersants for concrete can be used. These dispersants may be used in combination of two or more.

The amount of the dispersant used depends on the type, particle size and amount of the latent hydraulic substance used, the type and amount of the boron compound used, etc., but the total amount of the latent hydraulic substance and the boron compound is 100% by weight. The amount is usually 0.1 to 10 parts by weight, preferably 0.3 to 7 parts by weight, particularly preferably 0.5 to 5 parts by weight based on parts. If the amount of the dispersant is less than 0.1 part by weight, the dispersibility is undesirably deteriorated depending on the amount of water to be added. Even if it is used in an amount of 10 parts by weight or more, the effect corresponding to the added amount cannot be obtained, which is economically disadvantageous.

The amount of water used varies depending on the type, particle size and amount of the latent hydraulic substance used, the type and amount of the boron compound used, etc., but is based on 100 parts by weight of the total amount of the latent hydraulic substance and the boron compound. And usually 10 to 60 parts by weight, preferably 15 to 40 parts by weight, more preferably 18 to 30 parts by weight. If the amount is less than 10 parts by weight, it becomes difficult to obtain a liquid state, which is not preferable. When used in an amount of 60 parts by weight or more, dispersibility can be obtained, but long-term stability is deteriorated, which is not preferable. Generally, when the amount of the dispersant added is increased, the amount of water required for dispersion tends to be small.

When the treating agent of the present invention has a liquid composition, the treating agent of the present invention optionally contains a thickener. The thickener has the effect of improving the viscosity of the liquid composition and suppressing the sedimentation of the dispersed latent hydraulic substance powder particles (improving storage stability). The thickener is not particularly limited as long as it is water-soluble. However, there is a thickener which forms a complex depending on the type of boron compound, and it is preferable to avoid such a thickener. Acrylate, poly (meth) acrylamide, (meth) acrylic acid / (meth) acrylamide copolymer salt, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyethylene oxide, polypropylene oxide, polyvinyl Specific examples in which relatively high molecular weight compounds such as pyrrolidone, polyvinyl alcohol, xanthan gum and the like can be used include, but are not limited to, these. Further, two or more of these thickeners may be used in combination.

The molecular weight of the thickener used depends on the type of the thickener, the type and the particle size of the latent hydraulic substance to be used, and cannot be described uniformly, but the viscosity of the aqueous solution can be used as a standard for selection. I can do it. For example, 0.2 of thickener
For example, if the weight% aqueous solution is 50 c
Thickeners that are not less than ps are preferable, those that are not less than 100 cps are more preferable, and those that are not less than 150 cps are particularly preferable. The amount of the thickener used depends on the type of the thickener, the type and the particle size of the latent hydraulic substance to be used, and cannot be described uniformly.
The amount is 0.01 to 5 parts by weight, preferably 0.02 to 3 parts by weight based on 00 parts by weight.

Since the heavy metal treating agent of the present invention contains a latent hydraulic substance and a boron compound as main components, it has a drawback that it absorbs moisture during use or storage and hardens as in the case of using cement, and cannot be used. This is advantageous in terms of equipment maintenance, since there is no possibility that the solidified material will not adhere to the inner wall of the device unless the device is washed with water within several hours after use and the device itself cannot be used. In addition, there is an advantage that the powdery composition can be handled as a liquid composition in the form of a slurry as described above when it is possible to handle the powdery work but dislikes the powder work. Another advantage that can be handled as a liquid composition is that the volume is smaller than that of storing as a powder, so large equipment such as silos is not required, and mixing and kneading with heavy metal-containing waste is easy. Can be mentioned.

In the case of heavy-metal municipal incineration fly ash, etc., in which the elution solution of the heavy metal-containing waste in the dissolution test described in Announcement No. 13 is highly alkaline, amphoteric heavy metal compounds such as lead compounds are easily dissolved. , Nitric acid, poly aluminum chloride,
Addition of an acidic substance such as an inorganic acidic substance such as ferrous chloride, ferrous sulfate, or aluminum sulfate, or an organic acidic substance such as acetic acid or citric acid to control the pH to a weak alkalinity can stabilize the heavy metal of the treating agent of the present invention. Effect is enhanced. In addition, when the eluate in the dissolution test of Announcement No. 13 is a waste containing heavy metals such as electric furnace ash, melt fly ash, and contaminated soil that is neutral or acidic, the treating agent of the present invention may be treated with sodium hydroxide, hydroxide or the like. Hydroxides of alkali metals such as potassium, carbonates of alkali metals such as sodium carbonate and potassium carbonate, hydroxides of alkaline earth metals such as calcium hydroxide, magnesium hydroxide and barium hydroxide, sodium silicate and potassium silicate ,
Add a basic substance such as alkali metal silicate such as sodium metasilicate and sodium orthosilicate, alkali metal phosphate such as monosodium phosphate and disodium phosphate, cement, cement clinker, etc. to make the pH weakly alkaline. When controlled, the effect of stabilizing heavy metals of the treating agent of the present invention is enhanced.

The amount of the acidic substance or the basic substance to be used is preferably such that the pH of the eluate after the dissolution test described in Announcement 13 can be adjusted to 8 to 12. The basic substance or the acidic substance may be added in advance to the treating agent of the present invention, but may be used in the stabilizing treatment method of the present invention described later.

Further, in the treating agent of the present invention, various admixtures may be used as necessary for the purpose of improving the moldability of the treated heavy metal-containing waste. Specific examples of the admixture that can be used include pulverized slow-cooled slag, ferrochrome slag, silica, alumina, talc, silica sand, silica powder, clay, kaolin, calcium carbonate, crushed ceramics, titania, zirconia, and river sand. Filler, glass fiber,
Fibers such as carbon fiber, vinylon fiber, nylon fiber, aramid fiber, polypropylene fiber, acrylic fiber, and polyester fiber, and fibers such as cellulose fiber, steel fiber, and alumina fiber are exemplified. Further, a curing retarder such as sugar and glucose, a surface treating agent such as a silane coupling agent, a pigment, and the like may be used as necessary.

The treating agent of the present invention can be obtained by uniformly mixing the above components at a predetermined ratio. When the powdery treatment agent of the present invention is obtained, the respective components may be powder-mixed by a known mixing method. The method of mixing when obtaining the liquid treatment agent of the present invention is not particularly limited, but a predetermined amount of a dispersant, water, and, if necessary, a thickener used are mixed to form an aqueous solution. The method of adding to the mixed powder components such as the latent hydraulic substance and the boron compound is preferable because the whole becomes easily uniform.

The method for stabilizing heavy metal-containing waste of the present invention (hereinafter referred to as the processing method of the present invention) comprises a treating agent of the present invention,
Mix and knead the heavy metal-containing waste and, if necessary, water.
Water is added when the heavy metal-containing waste does not contain water, or when it is contained but insufficient for mixing and kneading. The amount of water used depends on the water content of the heavy metal-containing waste and its particle size.
5 to 80 parts by weight with respect to 0 parts by weight (calculated in a dry state),
Preferably it is 10 to 50 parts by weight. However, this amount differs depending on the shape of the treated body after the stabilization treatment is performed, that is, whether it is pelletized, granulated, or muddy. . The time required for the treatment (mixing, kneading time) is not particularly limited,
It is only necessary that the waste and the treating agent can be uniformly kneaded. The equipment for mixing and kneading them and the order of adding them are not particularly limited. The treatment agent of the present invention mixed in advance may be mixed with heavy metal-containing waste, or each component constituting the treatment agent of the present invention may be mixed with heavy metal-containing waste. The mixing method can be, for example, a kneader-ruder type or an Erich-type mixing and kneading machine with a stirrer when performing a batch process, and during air or liquid transportation when performing a continuous process. Mixing method using kinetic method,
A single-shaft or twin-shaft paddle-type kneader, a pan-type mixer, a vibro mixer, or the like can be used.

In the treatment method of the present invention, the treatment agent of the present invention, the heavy metal-containing waste and water as an optional component are mixed, kneaded, or after mixing and kneading, and the kneaded material is subjected to a heat treatment to suppress heavy metal elution. This is preferable because the effect is significantly improved and the time required for stabilization can be reduced. In the heat treatment, heat generated during kneading may be used, or the kneaded material may be heated as it is or after kneading. Heating temperature is 40 ° C or higher, preferably 50 ° C
That is all. The heating method may be a known method such as a mechanical method or a physicochemical method as described above. The heating time is
It depends on the thermal conductivity, size, heating method, etc. of the kneaded material or the processed material and cannot be said uniquely, but is usually 5 minutes or more, preferably 10 minutes or more, and the uniformity and workability of the processed material Up to 24 hours from the surface is sufficient.

There is no particular limitation on the waste which can stabilize heavy metal ions by the treatment agent and treatment method of the present invention.
Industrial wastes including municipal incineration ash and fly ash, contaminated soil, sludge, or metals that must satisfy the criteria set forth in Prime Ministerial Decree No. 5 can be treated alone or in combination. When stabilizing municipal incineration fly ash by the treatment method of the present invention, the treatment agent of the present invention is added to the flue together with slaked lime and activated carbon, and the heat of the flue is utilized simultaneously with the treatment of exhaust gas such as HCl and dioxin. This is convenient because it can stabilize heavy metals. In this case, the treatment agent of the present invention may be previously mixed with slaked lime or activated carbon,
A powdery or liquid treatment agent of the present invention may be sprayed into the flue.

According to the treating agent and the treating method of the present invention, the heavy metals in the heavy metal-containing waste are stabilized, and the heavy metals are hardly eluted from the kneaded material after the treatment. In the metal elution test using the method for detecting harmful substances contained in industrial waste specified in the above, all the elution amounts of heavy metal ions are below the landfill regulation value of Prime Ministerial Ordinance No. 5.

The treated product of the present invention thus obtained may be used as it is or may be pulverized as necessary to be used as aggregate for cement / concrete or aggregate for road pavement. It can be used as civil engineering and construction materials by molding into a shape.

[0033]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 5 To 100 parts by weight of granulated blast furnace slag having a Blaine specific surface area of 4,000 cm ² / g, sodium tetraborate was powder-mixed with the respective amounts shown in Table 1 to obtain a treating agent ( (Hereinafter referred to as treatment agent)
I got Incineration fly ash obtained from an incineration plant for municipal waste (lead content: 1960 mg / kg, lead elution amount based on Environmental Notification No. 5
3.4 ppm) (hereinafter referred to as A fly ash) 100 parts by weight and 5 parts by weight of the above-mentioned treating agent were added and mixed, and 33 parts by weight of water was added and kneaded. Table 1 shows the results of a dissolution test based on the above. Table 1 shows the amount of lead eluted after curing at room temperature for one week or more.

[0035]

Table 1 Table 1 Sodium tetraborate Annealing No. 13 Lead elution amount (ppm) content (parts by weight) 1 day after 1 week after 4 weeks after 8 weeks Example 15 0.27 0.25 0.20 10 0.02 Example 2 10 0.21 0.20 0.08 0.01 Example 3 50 0.15 0.10 0.01N. D. Example 4 100 0.12 0.08 N.P. D. N. D. Example 5 300 0.08 0.05 N.P. D. N. D. Note that in Table 1, N.I. D. Indicates 0.01 ppm or less (the same applies hereinafter).

Examples 6 to 10 To 100 parts by weight of the heavy metal-containing waste shown in Table 2, 2.5 parts by weight of granulated blast furnace slag and 1.5 parts by weight of silver tetraborate mixed in advance with powder were added. After adding the amount of water shown in Table 2 and kneading, the mixture was cured for 24 hours and subjected to a lead elution test based on Notification No. 13 of the Environment Agency. The results are shown in Table 2.

[0037]

Table 2 Water addition amount of waste Announcement No. 13 Lead elution amount (parts by weight) Lead elution amount (ppm) (ppm) Example 6 B fly ash 42.325 0.19 Example 7 C incineration Gray 0.98N. D. Example 8 D incineration ash + fly ash 26.1 12 0.23 Example 9 E concentrated waste liquid 12.3 0.28 Example 10 F sludge 8.35 0.12

Examples 11 to 16 Powders were obtained by mixing 50 parts by weight of various boron compounds with 100 parts by weight of fly ash A and 50 parts by weight of granulated blast furnace slag having the specific surface area of branes shown in Table 3. After adding and mixing 10 parts by weight of the treating agent and adding and mixing 32 parts by weight of water, the mixture was cured under the processing conditions shown in Table 3 and subjected to a dissolution test based on the notification of Environment Agency Notification No. 13 in Table 3. Are also shown.

[0039]

Table 3 Table 3 Blaine Boron compound Treatment conditions Annealing No. 13 Type of specific surface area (° C-hour) Lead elution amount (ppm) (cm ² / g) Example 11 2,000 Tetraboric acid 40-18 12 Sodium Example 12 4,000 Tetraboric acid 55-12 0.18 Calcium Example 13 6,000 Borax 60-8 0.27 Example 14 8,000 Ethyl borate 80-4 0.009 Example 15 _{10,000 B 2 S 3 90- 2 0.} 12 example 16 15,000 BPO ₄ 40- 24 0. 06

Examples 17 to 20 70 parts by weight of granulated blast furnace slag having a specific surface area of 4,000 cm ² / g and 30 parts by weight of potassium tetraborate were mixed with sodium salt of a copolymer of acrylic acid and maleic anhydride (average). (Molecular weight 45,000) 2 parts by weight, water 20 parts by weight, and polyacrylamide having an average molecular weight of 2,000,000.
One part by weight was added and mixed to obtain a liquid heavy metal-containing waste treating agent of the present invention. The viscosity of this treatment agent after preparation is 2,50.
It was 0 cps (B-type viscometer). One week or one month after standing in a container, pseudo-coagulation occurred. However, when vibration was applied, the liquid recovered to a liquid state, and the viscosity was measured to be 2,400 cps and 2,200 cps, respectively. Also,
After preparation, it can be stirred continuously in the container,
By stirring intermittently every day to three days, the liquid state after the preparation was maintained for one month or more. One week after the preparation, this liquid heavy metal-containing waste treating agent of the present invention and water were used in the amounts shown in Table 4, respectively, and kneaded with fly ash A, then cured for 24 hours at room temperature and then notified to the Environment Agency. Leaching test of lead based on No. The results are shown in Table 4.

[0041]

Table 4 Amount of treatment agent added Amount of water added Lead No. 13 Lead elution amount (ppm) (parts by weight) (parts by weight) 1 day after 1 week after 13 weeks Example 17 5 28 0.270 .11 N.P. D. Example 18 8 26 0.16 0.10 N.I. D. Example 19 10 25 0.09 0.03 N.I. D. Example 20 15 21 N.P. D. N. D. N. D.

Examples 21 to 23 3 parts by weight of granulated blast furnace slag having a specific surface area of 4,000 per 100 parts by weight of electric furnace ash generated by a G steel company.
The treatment agent of the present invention consisting of 3 parts by weight of sodium tetraborate and the amount of calcium hydroxide shown in Table 5 and water were added and kneaded. Was subjected to a dissolution test. The results are shown in Table 5.

[0043]

Table 5 Table 5 Amount of water added to the treating agent of the present invention Eluate Annealing No. 13 pH of calcium hydroxide (parts by weight) Lead elution amount (ppm) Compounding amount (parts by weight) Untreated ash 0 25 7 0.2 9.6 Example 21 1.5 26 9.8 0.02 Example 22 226 10.3 0.04 Example 23 2.5 27 11.1 0.07

[0044]

The treatment agent for heavy metal-containing wastes of the present invention comprises:
It is suitable for stabilizing heavy metal-containing waste, and can stabilize the elution of heavy metal ions to a high degree, and its effect is continuous. Further, the treatment method of the present invention can easily stabilize a heavy metal-containing compound without using a special apparatus. Furthermore, since the treated product obtained by the treatment method of the present invention can impart strength equal to or higher than the solidification of cement, it can be recycled as civil engineering and building materials such as aggregates and paving materials.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B09C 1/08 B09B 3/00 304K C09K 17/02 // C09K 103: 00

Claims (10)

[Claims] 1. A treatment agent for heavy metal-containing waste, comprising a latent hydraulic substance and a boron compound. 2. The treating agent according to claim 1, wherein the latent hydraulic substance is granulated blast furnace slag. 3. The treating agent according to claim 1, wherein the boron compound is a boric acid compound. 4. The method according to claim 1, further comprising a dispersant and water.
The treatment agent according to any one of the above. 5. A heavy metal-containing waste, a treating agent according to any one of claims 1 to 4, and water if necessary.
A method for treating heavy metal-containing waste, comprising mixing and kneading. 6. A heavy metal-containing waste, the treating agent according to any one of claims 1 to 4, and water as required, followed by mixing and kneading, followed by heating to 40 ° C. or more. To treat heavy metal-containing waste. 7. The incineration ash of a heavy metal-containing waste in a garbage incineration plant,
7. The method for treating heavy metal-containing waste according to claim 5, wherein the waste is fly ash, contaminated soil, or industrial waste containing metals that must satisfy the criteria set forth in Prime Ministerial Decree No. 5. 8. The treatment agent and the acidic substance according to any one of claims 1 to 4, wherein the pH of the eluate after the dissolution test based on the notification of the Environment Agency No. 13 is basic, and the waste is a heavy metal-containing waste. The treatment method according to any one of claims 5 to 7, wherein the treatment is carried out by adding. 9. The treatment agent and the base according to claim 1, wherein the pH of the eluate after the dissolution test based on the notification of the Environment Agency No. 13 is neutral or acidic, and the waste is a heavy metal-containing waste. The treatment method according to any one of claims 5 to 8, wherein the treatment is performed by adding a toxic substance. 10. A processed product obtained by the processing method according to claim 5.